
The receiver's frequency is marked on its rear panel or on the bottom of the outer
cover.
The transmitter frequency is marked on the data label on the side of the battery
compartment. If the transmitter and receiver frequencies are not precisely the
same, the frequency of one of the units must be changed. It is usually easier to
change the frequency of the receiver; however, it is advisable to return both units
to the factory or authorized service location when changing frequencies, to ensure
the best results. Because of the very high performance of these units and the
specialized test equipment required to adjust them properly, it is not
recommended that users attempt to change frequency themselves.
If two or more systems are to be used in the same location, proper frequency
selection is required to avoid possible interference. Vega offers a free frequency-
coordination service for purchasers of our equipment. Frequencies are selected by
computer to avoid any possible interference from other wireless systems and
broadcast stations. Individuals wishing to take advantage of this free service
should contact the Vega factory or their local Vega sales representative.
Microphone Usage
The T-677 Series PRO PLUS DYNEX®III UHF bodypack transmitter is
designed to operate with lavalier microphones; however, with a Model 114
adapter cable, many standard wired handheld microphones may also be used.
Because the audio circuits in the transmitter have been optimized for use with
lavalier electret (condenser) microphones, certain types of low-output dynamic
microphones may not be able to drive the transmitter adequately. In these cases, it
may be necessary to use an impedance-matching transformer at the microphone or
an internally powered condenser microphone. The T-677 Series transmitters
cannot phantom-power wired handheld microphones.
The vast majority of available lavalier microphones are of the electret condenser
type. The T-677 Series specifically includes bias circuits for powering this type of
microphone. However, most lavalier electrets are equipped with electronics
modules containing voltage-regulator circuitry (or a battery compartment) and a
transformer for the line output. Many are designed for phantom-powering through
the microphone cable. When used with the T-677 Series transmitter, it is almost
always necessary to detach the electronics module and interface the electret
element directly to the transmitter circuitry. Connection data for the more popular
lavalier electret microphones was included with this transmitter. If a microphone
other than those listed is to be used, Vega will attempt to assist in determining the
correct connections. Please contact Vega or your Vega sales representative if
assistance is required.
Preparation for Use
(1) Battery Installation—Slide battery-compartment cover on the bottom of the
unit out either side of the unit. Hold the battery-removal pull tab out of the way.
Insert battery; the smaller positive terminal goes in first. Hold the battery-removal
pull tab against the battery and slide the cover back in place. Turn the transmitter
“on” by means of the power switch on the front panel of the unit. The
COMPRESSION/BATTERY LOW indicator LED on the front panel should blink
on once and go out, indicating that the battery has adequate voltage to operate the
transmitter. If the LED remains on or does not blink once when the power is
turned on, the battery may be very weak or “dead”. If this occurs, replace the
battery with a known fresh unit. NOTE: This is a high powered transmitter which
draws heavy current from the battery. Use only premium quality alkaline or
4
Model T-677 PRO PLUS DYNEX
®
III